My typical workflow involves using the lens correction profiles in the develop section of Lightroom 4. During the testing of the D800, using the Sigma 15mm lens and a ZEN 230mm dome, I noticed that the corners on the images were very soft.

I put this down to a hardware issue and started experimenting with extensions on the dome to overcome the softness.

However, I was looking at the images in LR and noticed that when i removed the lens correction, the softness/distortion went away!

The Sigma 15mm lens profile seems very off!

If you are getting weird soft corners with this lens, this may be a possible reason! Saying that, perhaps this is something that is happening with my installation of LR, has anyone else found anything similar?

I have seen the same with D700/Sigma 15
It looks like the "correction" tries to make something that looks like a non-fisheye-image, which is not what I wanted at all.
Basically I stopped using it, both over and under the surface

I'm not familiar with Lightroom (I use Photoshop) but what exactly is this lens correction trying to achieve - a rectilinear image from a fisheye shot? Domes create distortion (because they are just a simple spherical lens placed in front of the sophisticated camera lens) as well as the lens, so an above water correction may well not work with the lens when its used behind a dome underwater because of the additional distortions added by the dome. These distortions will almost certainly vary depending on the subject distance and consequent focus setting, and additional distortions and aberations will occus as you focus closer. [Even with flat ports the amount of correction of chroma needs varied adjustment for different focussed distances so I'm sure the same (but worse) applies to domes too.]

I buy my own photographic kit. Diving equipment manufacturers and diving services suppliers get even-handed treatment from me whether they choose to advertise in the publications I write for or not. All the equipment I get on loan is returned as soon as it is finished with.Did you know you can now get Diver Mag as an iPad/Android app?

I was working on some shots from Salt Pier, Bonaire. I didn't like the distortion on the pilings. The Lens profile default over-corrected. I pulled back on the distortion slider and that seems to do the trick. Unless there are obvious parallels in the photo, I would leave the lens profile off in this case.

Cheers,
Marli

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Marli Wakeling

www.marliwakeling.comDuct tape is like the force. It has a light side, a dark side, and it holds the universe together. ~Carl Zwanzig

Yes, good example of where fisheyes aren't nice and a rectilinear WA is nicer. I do understand that rectilinear WA have their own issues with complex distortion and dome pairing...but the former is subtle and the latter seems solveable. So far, I still prefer trying to shoot with the 8-16mm and haven't even attempted taking the 10mm FE under.

I was going to post that I bet the lens correction was assuming normal optical use in 'air' and the extra air/water interface distortions behind a dome were defeating it, but I see I got beaten to the punch on that....